Composite inking and obliterating typewriter ribbon

ABSTRACT

A class of &#39;&#39;&#39;&#39;self-correcting&#39;&#39;&#39;&#39; typewriter ribbons is described, having an inking portion and an obliterating portion, whose members share the common property of having those portions spaced apart from one another by a gap (either edgewise or face-wise) to ensure against transfer of ink to the obliterating material. The gap facilitates manufacture, and in one form, or group of forms, a metallic layer on one of the portions is used to reduce friction in the ribbon guides, improve the appearance of the ribbon, and provide a visual indication to the user that the ribbon is properly installed for use.

United States Patent Wolowitz [76] Inventor: William H. Wolowitz, 6905Persimmon Tree Rd., Bethesda, Md. 20034 [22] Filed: Mar. 26, 1973 [21]Appl. No.: 345,127

[52] U.S. Cl. 197/172, 197/181 [51] Int. Cl B41j 31/02 [58] Field ofSearch 197/172, 181

[56] References Cited UNITED STATES PATENTS 455,263 6/1891 Rogers197/172 1,905,118 4/1933 Nadell l97/18l 1,953,316 4/1934 Stark 197/1722,174,351 9/1939 Neidich.... 197/172 2,255,104 9/1941 Dixon r r 197/1722,728,439 12/1955 Murphy et al.. 197/172 2,830,689 4/1958 Clancy etal.... 197/172 3,114,447 12/1963 Wolowitz r 197/172 3,141,539 7/1964Wolowitz.... 197/181 X 3,143,200 8/1964 Gutman 197/172 re/ease Coabirg24 Primary Examiner-Ernest T. Wright, Jr. Attorney, Agent, or Firm-HomerR. Montague, Esq.

[ 5 7 ABSTRACT A class of self-correcting typewriter ribbons isdescribed, having an inking portion and an obliterating portion, whosemembers share the common property of having those portions spaced apartfrom one another by a gap (either edgewise or face-wise) to ensureagainst transfer of ink to the obliterating material. The gapfacilitates manufacture, and in one form, or group of forms, a metalliclayer on one of the portions is used to reduce friction in the ribbonguides, improve the appearance of the ribbon, and provide a visualindication to the user that the ribbon is properly installed for use.

8 Claims, 7 Drawing Figures COMPOSITE INKING AND OBLITERATING TYPEWRITERRIBBON BACKGROUND OF THE INVENTION In my previous patents such as US.Pat. No. 3,1 14,447, US. Pat. No. 3,141,539, and British specificationPat. No. 961,108, Published June 17, 1964 (Crown Copyright 1964), Itaught various ways of constructing self-correcting typewriter ribbonshaving respective portions for typing and for obliterating, saidportions occupying in a general way the areas theretofore devoted tomulti-color inks such as black and red. Such prior constructions, thoughquite practical, were relatively complex, requiring numerousmanufacturing steps, and frequent rolling up and rewinding of thevarious materials comprising the ribbons. Moreover, the finished ribbonswere often of relatively short life, in part due to migration of the inkfrom the printing area into the area devoted to the cover-up orcamouflage material, with consequent deterioration and discoloring ofthe latter.

Some of the competitive ribbons marketed by others contained entirelyincompatible materials; in this connection, it may be mentioned thateven if such intermixture of materials happened or occurred to somelimited degree (not in itself harmful to the properties of the ribbon),it often resulted in an unsightly product having poor customeracceptance. However, depending on the materials involved, migrationmight entirely vitiate the effectiveness of the correcting or cover-upportion of the ribbon.

In addition to the above considerations, it will also be observed thatmigration of the ink into portions of the ribbon which are not used orintended for making impressions, depletes the volume of the ink that isavailable for printing, and therefore operates to shorten the ribbonslife in a way that is quite distinct from that described above.

Finally, self-correcting ribbons of previously described types, both ofmy own invention and of the constructions of others, have proven insortie cases to be too thick to traverse freely in the ribbon guides andvibrators of certain typewriters. This is most noticeable in latermodels of the Smith-Corona electric portables, and in some models of theOlivetti machines, and is usually caused by the extra or addedthicknesses of the layers, one or more, needed in connection withproviding the self-correcting feature.

Besides other objectionable characteristics (such as frictionaldestruction of the correction material traversing too tight guides andvibrators), such combinations interfere with the free upand-downmovement of the vibrator, which in turn prevents full and satisfactorycorrection of mistakes. Such troubles are magnified where the entireback of the ribbon is covered by a protective layer, and especially ifthe said layer is of a type which grows" dimensionally as it issubjected to the impacts of typing.

SUMMARY OF THE INVENTION The invention provides a number of varieties ofselfcorrecting typewriter ribbons which are completely free from thetransfer of ink onto the camouflage material, whether that ordinarilyresulting from edgewise migration, osmosis or the like, or fromface-to-face contact such as occurs during rolling-up (especially,

. 2 and initially, at the edges) of the ribbon. The invention furthercomprehends composite or self-correcting ribbons which do notnecessarily have any regions that are thicker than an ordinarynon-correcting ribbon, and indeed may in every part be thinner than suchan ordinary ribbon. The novel ribbons may also have their major parts(inking portion and correcting portion) precisely equal in thickness,for evenness of spooling and maximum yardage per spool. The latter is ofespecial importance when the ribbon is not spooled in the ordinaryfashion, but is used in one of the new ribbon magazines or cartridgeswhcih have at best relatively limited ribbonlength capacity. In suchapplications, maximum thinness is an important desideratum if adequateusable ribbon-life is to be obtained.

In many forms which the ribbons of this invention may take, theprovision of a metallic layer incorporated in or on the obliteratingportion or component, provides important advantages, including reduceddrag or friction in the guides and the vibrator, visual guidance as anaid to manufacture as well to installation, and vastly improvedappearance of the product.

FIG. 1 is a perspective view of a typewriter ribbon in accordance withthe invention, with a portion shown greatly enlarged and in section.

FIG. 2 is a transverse sectional view of a slightly modified form of aribbon, further enlarged.

FIG. 3 is a view similar to FIG. 2, but of a slightly different form ofthe invention.

FIG. 4 is another view similar to FIG. 2 of still another form of thenovel ribbon.

FIG. 5 is a view similar to FIG. 1 showing a modified form of the ribbonof the invention.

FIG. 6 is a further enlarged sectional view of the ribbon shown in FIG.5.

FIG. 7 is a further and additionally enlarged sectional view of aportion only of FIG. 5, particularly illustrating the manner of assemblyof that ribbon.

In FIG. 1, the ribbon spool has wound thereon a composite inking andobliterating ribbon comprising the upper portion 10 which is preferablyformed of woven nylon fabric, and a lower portion 12 consistingprincipally of a thin, flexible ink-impervious strip of plastic such asCapran, or Mylar which has been treated to render the sameheat-scalable. The two portions divide the width of the ribbonapproximately between them, and the ink-impervious strip 12 forming thelower portion overlaps the upper portion 10 (the inkimpregnated portion)and is heat sealed thereto by a row of intermittent heat seals 14,stitches, sutures or the like. Numeral 16 indicates a similar row ofheat seals securing to one surface of portion 12 a thin, flexiblecarrier strip 18 preferably of Mylar plastic, having a very thin, shinyouter layer or coating of metal 20;

A support layer or strip 22 (which may be thin, heatsealable plastic) issecured to the other surface of portion 12, and this in turn carries therelease" layer 24 of correction or camouflage material. The securing ofstrip 22 to the portion 12 may be by virtue of a cut heat-seal at, andthrough, the lower edges of all three layers, as at 26.

FIG. 2 is a sectional view of such a ribbon, further enlarged forclarity, which exactly corresponds to the FIG. 1 construction, exceptthat a second row of intermittent heat seals, exactly duplicating thestitches 14,

highly visible during manufacture, as is the location of the line ofstitches or sutures, and of course the metallic layer is also a definiteindication to the user that the ribbon has been properly installed inthe typewriter or other business machine. Both ribbons exhibit theimportant thinness considerations mentioned above.

In FIG. 3, the inking portion of the composite ribbon comprises thewoven fabric portion 30 (typically nylon) and a backing layer of verythin ink-impervious plastic film 32 (typically Capran). The overlappingstrip, typically also of Capran, is indicated at 34, an intermittentheat seal of stitches or the like at 36, and the carrier for the releaseor camouflage layer at 38. The bottom cut heat seal is at 40. In thisembodiment, the backing layer of film 32 gives the usual advantage ofprotecting the type faces from ink, lint and so on, but it also has thedisadvantage that the film 32 grows" in both directions as it isrepeatedly impacted in normal use, with the well-known objectionableresults.

FIG. 4 illustrates a variation of the invention particularly useful whenadditional strength is desired in the bond securing the inking portionto the obliterating portion. The inking portion is represented by thewoven fabric (nylon) ribbon 42, secured to inkimpervious strip 44 by aline-weld 46 as previously described. A second ink-impervious strip 48also overlaps the ribbon 42, and is secured to the latter by a line-weld50. The obliterating component (that is, a release layer or coating 52)is carried by strip 48, and the bottom edges of the various strips areconnected by a heat seal 40 as described above. It will of course beunderstood that this last-mentioned heat seal may be that resulting fromthe heated cutting means used to sever two duplicate halves from oneanother, a well-known method of fabricating all of the composite ribbonsdescribed herein.

In FIG. 5, the inking portion of the composite ribbon is designated 54,and it has secured to it, by a preferably intermittent line 55 of heatseal stitches or sutures, the overlapping thin, flexible ink-impervioustransparent strip 56. In this form of the invention, the strip 56 iscompletely free from other layers or coatings on the surface facing awayfrom the inking portion 54. The release layer of camouflage material isindicated at 58, and it is separate from, though directly in contactwith, the very thin, flexible metallic layer 60 in turn carried by strip56. The metallic layer 60 is thus visible through the transparent strip56.

The above construction is shown to larger scale (sim ilarly to FIG. 2)at FlG. 6, where the release layer 58 and the underlying metallic layer60 bear the same numbers as before. However, a physical (transparent)carrier 62, typically of Mylar, is shown and may be provided to addstrength, facilitate manufacture, signal correct installation, andeven-out the thickness of the main portions of the composite ribbons, etcetera. Carrier 62 may be welded to strip 56 as heretofore disclosedabove.

FIG. 7 shows a portion of the construction of FIGS. 5 and 6 to a stillmore enlarged scale. It must be understood that in all the figures, therelative thicknesses of 5 the layers, strips, et cetera are onlyapproximated. Thus, in the original patent drawing, the nominal halfinchcomposite ribbon (FIG. 2) is about 6 inches wide a ratio of 12:1enlargement. Assuming a typical and nominal ribbon thickness of 4 mils(0.004 inch), the thickness shown in FIG. 2 should be 12 times 0.004inch, or nearly 0.05 inch, equivalent to 1/20 of an inch. Clearly, anyshowing of structure within that thickness would not be reproducible asan illustration, so that any physical layers are grossly exaggerated asto thickness.

ln FIG. 7, for example, the metallic coating 60 would be of negligiblethickness, being much less than 0.1 mil. Also, the release layer 58might be negligible in thickness, as of the order of 0.5 mil. Hence, theevening out of a total equivalent thickness of 0.004 inch, could bedivided in any ratio required by other considerations. As a practicalmatter, human fingers cannot detect a transition in thickness as betweenthe composite ribbon portions made according to either FIG. 1 or FIG. 5;this represents a very striking advance in the art.

In all of the foregoing examples, the inking portion of the compositeribbon has been a woven, textile fabric impregnated with ink. it is notan absolute necessity that this be so, in that the inking portion couldin theory be constituted more like what is called a "one-time"carbon-coated plastic strip or film, although such would presentlyappear to be not economically feasible. However, I do not mean to whollyexclude such a construction from the purview of my invention.

What is claimed is:

l. A composite inking and obliterating ribbon for typewriters and thelike, comprising a first approximately half-width portion ofink-impregnated textile fabric, and the remaining width-wise portionconstituted by a thin, flexible ink-impervious strip overlapping saidfirst portion and secured thereto by said overlapping, said stripproviding on one surface thereof a deposit of camouflage transfermaterial; there being a gap between said first portion and said deposit.

2. A structure in accordance with claim 1, and a major part of the othersurface of said strip beyond the gap being covered by an opaqueink-impervious layer.

3. A structure in accordance with claim 2, in which said opaque layer isspecularly reflective.

4. A structure in accordance with claim 2, in which said opaque layer ismetallic in appearance.

5. A structure in accordance with claim 2, in which said opaque layer ismetallic.

6. A structure in accordance with claim 1, in which said fabric and saidstrip are mutually heat-scalable, and in which they are secured togetherby means of an intermittent heat seal, stitching or suture.

7. A composite inking and obliterating ribbon for typewriters and thelike, comprising a first approximately half-width portion ofink-carrying plastic film, and the remaining width-wise portionconstituted by a thin, flexible ink-impervious strip overlapping saidfirst portion and secured thereto by means of said overlapping, saidstrip providing on one surface thereof a deposit of camouflage transfermaterial; there being a gap between said first portion and said deposit.

8. A structure in accordance with claim 7, in which said plastic filmand said strip are mutually heatsealable, and in which they are securedtogether by means of an intermittent heat seal, stitching or suture. i l

1. A composite inking and obliterating ribbon for typewriters and thelike, comprising a first approximately half-width portion ofink-impregnated textile fabric, and the remaining width-wise portionconstituted by a thin, flexible ink-impervious strip overlapping saidfirst portion and secured thereto by said overlapping, said stripproviding on one surface thereof a deposit of camouflage transfermaterial; there being a gap between said first portion and said deposit.2. A structure in accordance with claim 1, and a major part of the othersurface of said strip beyond the gap being covered by an opaqueink-impervious layer.
 3. A structure in accordance with claim 2, inwhich said opaque layer is specularly reflective.
 4. A structure inaccordance with claim 2, in which said opaque layer is metallic inappearance.
 5. A structure in accordance with claim 2, in which saidopaque layer is metallic.
 6. A structure in accordance with claim 1, inwhich said fabric and said strip are mutually heat-sealable, and inwhich they are secured together by means of an intermittent heat seal,stitching or suture.
 7. A composite inking and obliterating ribbon fortypewriters and the like, comprising a first approximately half-widthportion of ink-carrying plastic film, and the remaining width-wiseportion constituted by a thin, flexible ink-impervious strip overlappingsaid first portion and secured thereto by means of said overlapping,said strip providing on one surface thereof a deposit of camouflagetransfer material; there being a gap between said first portion and saiddeposit.
 8. A structure in accordance with claim 7, in which saidplastic film and said strip are mutually heat-sealable, and in whichthey are secured together by means of an intermittent heat seal,stitching or suture.